it´s important to start with fiendish codex for the early cooldown reduction, because essence flux is u prime damage source. Normaly mana should be no problem in early game, but with second blue buff mid lane gonna be fun :) dont be to aggresive in early cause if u shot all u skills., u cant do much for the nxt seconds. After reaching lvl 4 poke and harras with mystic shot, also very convinient because every hit of mystic shot gives u 1 sec cooldown reduction. If u want to engage u lane 1v1 start with arcane **** following essence flux and mystic shot. If u got sheen already u outhit should do an good amount of dmg too. then chase with mystic shot and arcane shift, to finish use trueshot barrage if necessary. In mid to end game, use u ultimate to poke and harras, dont forget to spam mystic shot to get Ult cd up again very fast. if u dont buld any mana item or take some mana pots with u, blue buff is NECESSARY, cause otherwise u cant poke enoug ;)
Hope u like my firt guide.